There is a great variety of weapon choices available that one can choose from when on the surface of the Earth, but once entering the vast realm of the undersea world, the choice of offensive or defensive weapons dwindles to almost nothing. About the only choices are a hand-held knife and a spear gun, which has very limited use. Spear guns typically involve a long spear with a pointed tip loaded in the spear gun. The spear gun typically shoots the spear via a rubber band or by pneumatic means. Usually, the spear is inserted in the barrel of an elastic band type gun until it is seated in the trigger mechanism. One or two spears in a spear gun have been described and after these are shot, the spear gun must be reloaded. Spear guns are usually long, cumbersome weapons and reloading them underwater is a widely recognized as a difficult task.
Use of paired electrodes generating electric fields within sea water has been described as a means for repelling sharks and for killing nuisance aquatic life. Devices similar to cattle prods have been described. These devices, when inserted by a dry user from above the water level into the sea or other body of water typically utilize two electrodes in close proximity and operate by passing current between the electrodes. None use a single electrode for electrocuting an underwater living being, and none involve use by submerged divers holding the device like a knife, a pistol or a spear gun.
Prior art also teaches the use of bang sticks that prod a fish and simultaneously discharge a power head or shot shell to kill or disable an aggressive sea creature, such as a shark or barracuda. The bang stick is a form of underwater firearm. Accidental discharge, single shot capability, close proximity and aiming difficulties make it desirable to have an easy to use alternative that a diver can use to quickly kill any approaching sea creature.